1. Field of the Invention
This invention relates to pallets made from molded plastic for holding liquid-filled drums.
2. Description of the Related Art
Plastic pallets have been developed in an effort to provide an adequate support structure for carrying liquid-filled drums, while at the same time being able to contain leaking fluid from leaky containers.
Different configurations have been attempted to provide molded pallets having sufficient structural strength to distribute weight during loading. For example, U.S. Pat. No. 3,702,100 to Wharton discloses a molded pallet having a generally corrugated structure, where the corrugations in the medial portion of the pallet are formed in concentric rectangles so as to reinforce each other and minimize distortion when racking. A series of spaced corrugations are also positioned in parallel relation to each side of the pallet. The disclosed pallet also includes ribs spaced between the corrugations to provide additional reinforcement and to act as stacking supports when the pallets are nested to prevent jamming and sticking of one pallet within another.
One problem associated with pallets is that the drums loaded on the pallet may begin to leak, which may cause severe environmental contamination if the leaking fluid is not contained. Although the pallet described in Wharton is not designed for the collection and retention of fluid, U.S. Pat. No. 5,359,955 to Grebenyuk discloses a spill pallet for supporting drums containing hazardous material, where the pallet includes a base and a grate upon which a number of drums are placed. The base includes a support surface which vertically abuts the grate, and bowl-shaped chambers positioned beneath the support surface to receive and contain spilled or leaked liquid. However, the relatively large size of the containers renders the pallet unstable when carried by a forklift. Moreover, the use of a two-piece pallet having a grate and a base with a chamber renders the pallet impractical for use and storage since the pallet requires two separate parts that must be kept together.
A more fundamental problem with the Grebenyuk pallet, as well as other prior art pallets, is that it is unable to identify the leaking drum because the bowl-shaped chambers are fluidly connected to optimize available retention volume, requiring a person to individually inspect each drum to determine which drum is leaking. If the leak is a slow leak, a person may be unable to determine the leaky drum at all. The use of a grate also covers the leaking fluid, preventing someone from visually observing the presence of a leak. Hence, a leaky drum may be left unnoticed, preventing a person to visually detect the leak and take corrective measures.